Sequential timing device for hand dryer and towel dispenser



Jan. 2, 1968 A. GOLDSTEIN 3,361,996

SEQUENTIAL TIMING DEVICE FOR HAND DRYER AND TOWEL DISPENSER Fi led Sept.14, 1966 2 Sheets-Sheet 1 INVENTOR Ann-we Comm ZM M ATTORNEY Jan. 2,1968 I A. GDOLDSTEIN 3,36

SEQUENTIAL TIMING DEVICE FOR HAND DRYER AND TOWEL DISPENSER Filed Sept.14, 1966 2 Sheets-Sheet z v e: i 12 Y A 3 I 19 r\ rE| I 16 0 f5 r\ rLMMQQQJ IN'VENTOR fig TH-u. GOA) TE TD/Md. M

ATTORNEY United States Patent 3,361,996 SEQUENTIAL TIMING DEVICE FORHAND DRYER AND TOWEL DISPENSER Arthur Goldstein, 375 Milton Road,Cambridge, England Filed Sept. 14, 1966, Ser. No. 579,240 Claimspriority, application Great Britain, July 22, 1966, 33,150/ 66 2 Claims.(Cl. 335-64) ABSTRACT OF THE DISCLOSURE returns the trip arm to aposition deactuating the first switch.

This invention relates to sequential timing devices.

It is an object of the invention to provide a simple and inexpensivedevice which will control an electric switch so that the switch will beheld open or closed for a predetermined time interval after each time ithas been operated. The invention is primarily intended for the controlof an electrical heater and blower in a hand drying device as describedin the specification of my co-pending patent application No. 417,085filed December 9, 1964, now patent 3,305,938. However, the invention isnot restricted to such use as it could be used with advantage for manyother purposes such as the control of traffic lights atpedestrian-operated crossings.

In the parent specification, there is described a sequential timingdevice comprising an actuating switch; an electric solenoid having acore which is displaceable from an inoperative position when theactuating switch is actuated, but which is free to return to theinoperative position when the solenoid is de-energized, a pair ofsuction cups one of which is carried by the core, the cups being soarranged that their faces are closed together when the core is displacedthereby to hold the core in the displaced position; an operating plungerwhich is carried by the core; and a controlled switch which is held openor closed as desired by the operating plunger when the core is in itsinoperative position, but which is movable to the closed or openposition when the core is displaced, air being permitted to enterbetween the cups after they have been closed whereby the cups will openafter a predetermined time to permit the core to return to itsinoperative position. The present invention provides a modification inwhich the actuating switch is actuated by movement of a trip arm and asecond electric solenoid is arranged to be energised by the actuatingswitch simultaneously with the first solenoid thereby to return the triparm to its inoperative position.

In the accompanying drawings:

FIGURE 1 is a sectional diagram illustrating and end of a hand dryingdevice which is a preferred embodiment of the invention, and

FIGURE 2 is an electric circuit diagram.

In the illustrated embodiment of the invention an apparatus for dryingthe hands is provided with an electric timing device comprising anelectric solenoid 1 (here inafter called the timer solenoid) mounted ina suitable bracket 2 on a housing 3 of the drying apparatus. The timersolenoid 1 has a core 4 which will be upwardly displaced when thesolenoid is energised by operation of a main actuating switch 5 which isa micro switch. When the timer solenoid is not energised,'the core 4will occupy a lower, inoperative position of rest.

The core 4 has an upper extension which carries the lower one (6) of apair of suction cups. The upper one (7) of these cups is supported byscrew 8 in the bracket 2 in an adjustable fixed position. The faces ofthe two cups 6, 7 are presented to each other and the cups are sopositioned that when the timer solenoid core 4 is raised, by energisingthe solenoid, the faces of the cups are closed together. This will causethe cups to be held together so that the core is held in its raisedposition. An air inlet 9 is provided so that air can enter between thecups when closed whereby the suction between the cups will be brokenafter a predetermined time dependent on the setting of the adjustableupper cup. The suction cups can be made of a combination of rubbertogether with a non-sticky substance such as polyethylene or P.TlF.E.

The core 4 has a lower extension or operating plunger 10 projectedbeneath the solenoid. This operating plunger 10 is engageable with anarm 11 of a switch 12 to be controlled. The arm 11 and/or the operatingplunger 10 is made of electrical insulating material. When the core isat its normal or inoperative position, the operating plunger is engagedwith the switch arm to press it down and hold the switch in the opencondition as shown in the drawing. When the actuating switch 5 isclosed, the timer solenoid 1 is energised to raise the core 4 andoperating plunger 10 thereby to enable the controlled switch 12 toclose. The same movement also closes the cups 6, 7 together. After thepredetermined time interval, the cups will open owing to the fact thatair can enter through the air inlet 9 thereby to enable the core andoperating plunger to fall so as to open the controlled switch.

If the actuating switch 5 is operated before the cups have opened, thedevice will be re-set so that the time interval desired will commence atthe time of re-setting.

The actuating micro-switch 5 is actuated by movement of a pivotallymounted trip arm 13 of insulating material. This trip arm 13 isconnected through a slip clutch 14- with an operating roller 15extending through the casing 3. A stack of paper towels T inside thecasing 3 rests on the roller 15 in such a way that the roller is rotatedwhen the lowermost towel in the stack is withdrawn for the purpose ofdrying the hands. This will pivot the trip arm 13 connected to theroller 15 and will therefore actuate the micro-switch. Thus, the timersolenoid 1 will be energised to set in operation for a limited period, ablower motor 16 and an electric heater 17. An electric pre heater 18remains permanently in operation.

The actuation of the actuating micro-switch 5 not only energises thetime solenoid 1, but simultaneously energises a trip arm solenoid 19,connected to the switch in parallel with the timer solenoid 1, todisplace a plunger 20 of that solenoid to return the trip arm 13 to itsoriginal position. Such return movement of the trip arm 13 against therotation of the roller 15 is permitted by the slip clutch 14. The returnmovement of the trip arm 13 opens the mirco-switch 5, but the controlledswitch 12 remains closed because of the action of the suction cups 6, 7.Return movement of the plunger 20 of the trip arm solenoid 19 isassisted by a spring 21.

The trip arm solenoid 19 provides a positive and effective means ofreturning the trip arm 13 to its normal or inoperative positionregardless of the Weight of the stack of towels T. This is ofconsiderable advantage as the weight of the towels obviously variesbetween a maximum when the casing 3 is fully charged with towels and aminimum when the casing is empty of towels. At maximum loading, the triparm will not always return positively unless assisted by the solenoid19.

What is claimed is:

1. A sequential timing device comprising an actuating switch; a trip armmoveable to actuate the actuating switch; a first electric solenoidenergizable in response to said actuating switch and having a core,which is displaceable from an inoperative position when the actuationswitch is operated, but which is free to return to the inoperativeposition when the solenoid is de-energised; a pair of suction cups oneof which is carried by the core, the cups being so arranged that theirfaces are closed together when the core is displaced thereby to hold thecore in its displaced position; an operating plunger which is carried bythe core; a controlled switch which is held open or closed as desired bythe operating plunger when the core is in its inoperative position, butwhich is movable to the closed or open position when the core isdisplaced, air being permitted to enter between the cups after they havebeen closed whereby the cups will open after a predetermined time topermit the core to return to its inoperative position and a secondelectric solenoid energizable in response to said actuating switch andbeing energised by operation of the actuating switch simultaneously withthe first solenoid to act on the trip arm to return it to its originalposition.

2. In an electric hand drying appliance including a towel container andan electric heater and blower, a sequential timing device comprising anactuating switch; a trip arm movable to actuatethe actuating switch; afirst electric solenoid energizable in response to said actuating switchand having a core which is displaceable from an inoperative positionwhen the actuation switch is operated, but which is free to return tothe inoperative position when the solenoid is tie-energised; a pair ofsuction cups one of which is carried by the core, the cups being soarranged that their faces are closed together when the core is displacedthereby to hold the core in its displaced position; an operating plungerwhich is carried by the core; a controlled switch responsive to theposition of said plunger and which is held open or closed as desired bythe operating plunger when the core is in its inoperative position, butwhich is movable to the closed or open position when the core isdisplaced, air being permitted to enter between the cups after they havebeen closed whereby the cups will open after a predetermined time topermit the core to return to its inoperative position, a second electricsolenoid energizable in response to said actuating switch and which hasa displaceable core and which is energised by operation of the actuatingswitch simultaneously with the first solenoid to displace the core, aplunger on the core and arranged to act on the trip arm and return it toits original position, an operating roller rotatable by withdrawal of atowel from the towel container, a slip clutch through which theoperating roller is connected to the trip arm so that rotation of theroller will actuate the trip arm.

References Cited UNITED STATES PATENTS 2,898,428 8/1959 Holden 200-172FOREIGN PATENTS 42,722 3/1938 Netherlands.

BERNARD A. GILH-EANY, Primary Examiner.

H. BROOME, Assistant Examiner.

